1. Field of the Invention
The present invention relates to solar powered street-lamps, and particularly to a control circuit capable of automatically controlling brightness of a solar powered street-lamp according to an environmental condition.
2. Description of Related Art
Nowadays, with the earth resources being depleted day by day, the cost of investment for energy increases significantly. Solar energy has drawn great attention from the energy industry as an alternative source of energy, and has found widespread applications in a variety of fields. For example, solar powered street-lamps are used in many countries.
A conventional solar powered street-lamp typically includes a solar energy operated absorption board, a storage battery, and a lamp. The solar energy operated absorption board absorbs solar energy and converts it into electric energy, which is used to recharge the storage battery. The storage battery supplies power to the lamp. However, the lamp typically works at a constant maximum power, i.e., the brightest state at all times. Therefore, the conventional solar powered street-lamp unnecessarily consumes a great deal of energy, thereby increasing costs and shortening its life span.
What is needed is a solar powered street-lamp control circuit for automatically controlling the brightness of the street-lamp according to environmental conditions.